Virulence genes profiles and phylogenetic origin of Escherichia coli from acute and chronic intestinal diseases revealed by comparative genomic hybridization microarray.

The association between Escherichia coli virulence factors and chronic intestinal disorders is mostly unknown. The presented study compared the distribution of virulence genes and phylogroups among E. coli isolated from chronic intestinal disorders such as Crohn's disease and irritable bowel syndrome (IBS) with strains isolated from patients with acute diarrhea as a control group. The presence of 159 virulence genes corresponding to known E. coli pathotypes was determined among 78 E. coli archive strains isolated from IBS, acute diarrhea and Crohn's disease using CGH microarray. E. coli isolated from IBS demonstrated a mosaic of virulence genes specific to enteropathogenic, enterotoxigenic, enterohemorrhagic E. coli strains and Shigella species. In contrast, virulence factors and phylogroups distribution among E. coli isolated from children with acute diarrhea was similar to extraintestinal E. coli strains that probably acquired some virulence genes. The acquisition of virulence genes might have an impact on diarrheagenic potential of these strains. On the other hand, E. coli isolated from children with Crohn's disease seem to be similar to adherent-invasive E. coli strains (AIEC), as it lack most known virulence genes. The presented study showed that these analyzed groups of E. coli strains differed from each other with the respect to the distribution of virulence genes. The differences in gene content support the idea that the participation of E. coli in chronic intestinal diseases is mostly related to virulence potential of these strains.